A kind of molybdenum tailings powder artificial aggregate and its preparation method and application

Abstract

The invention discloses a molybdenum tailings powder artificial aggregate and a preparation method and application thereof, which are used to solve the problem of resource utilization of molybdenum tailings. A molybdenum tailings powder artificial aggregate is composed of a powder component and a liquid component, wherein the liquid component is 15-35w parts of the powder component; based on each cubic meter of artificial aggregate, the powder component includes the following components: 50-70 parts of molybdenum tailings powder, 10-25 parts of cement, 3-12 parts of slag powder, and 5-10 parts of silica fume; the liquid component includes the following components: 35-55 parts of water glass, 2.5-4.5 parts of sodium hydroxide, 0.2-0.5 parts of water reducer, and 40-65 parts of water. Molybdenum tailings powder is the main component, which is mixed with cement, slag powder, and silica fume to form a spherical aggregate under the sticky action of the liquid component. The obtained aggregate solves the resource utilization of molybdenum tailings and reduces pollution to the environment. Also provided is a preparation method and application of molybdenum tailings powder artificial aggregate, which can be used as a raw material for concrete, achieving resource utilization of molybdenum tailings while ensuring the strength of concrete.

Description

Technical Field

[0001] The invention belongs to the field of building materials, and in particular relates to a molybdenum tailings powder artificial aggregate and a preparation method and application thereof. Background Art

[0002] With the rapid development of the national economy, the demand for molybdenum metal has gradually increased. Molybdenum metal has the characteristics of high conductivity, high strength, high melting point, and corrosion resistance, and is widely used in alloys, chemicals, electronics and other fields. The mining and processing volume of molybdenum ore in my country has also increased rapidly. Molybdenum tailings are the tailings left after the extraction of metallic molybdenum. my country is the world's largest molybdenum resource country, but due to the low molybdenum grade of molybdenum ore, in the process of extracting molybdenum resources with existing traditional technologies, more than 95% of the ore mining volume will be discharged as tailings. The accumulation of these molybdenum tailings not only wastes resources and occupies land, but also pollutes the surrounding environment. How to realize the resource utilization of molybdenum tailings is a technical problem that technicians in this field need to solve urgently.

[0003] The comprehensive utilization of molybdenum tailings mainly focuses on the extraction of valuable elements in molybdenum tailings and the preparation of new materials. In addition, molybdenum tailings contain some silicate minerals, so using molybdenum tailings powder as an admixture has become another important idea for the rational utilization of molybdenum tailings resources. Its comprehensive utilization of resources has become a major issue that needs to be solved in my country, such as protecting the ecological environment and eliminating safety hazards in tailings ponds. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of resource utilization of molybdenum tailings, and to provide a molybdenum tailings powder artificial aggregate and a preparation method and application thereof.

[0005] In the first aspect, a molybdenum tailings powder artificial aggregate adopts the following technical solution:

[0006] A molybdenum tailings powder artificial aggregate comprises a powder component and a liquid component. The powder component contains the following components in parts by weight per cubic meter of artificial aggregate: 50-70 parts of molybdenum tailings powder, 10-25 parts of cement, 3-12 parts of slag powder, 5-10 parts of silica fume, and 1-4 parts of gypsum; the liquid component accounts for 15wt%-35wt% of the mass percentage of the powder component.

[0007] By adopting the above technical solution, molybdenum tailings powder is used as the main component, and spherical aggregate is formed under the adhesive action of cementitious materials, slag powder, silica fume, gypsum and liquid components. The obtained aggregate solves the resource utilization of molybdenum tailings and reduces pollution to the environment.

[0008] Silica fume can improve the microstructure of cement paste. It has excellent activity. The silicon dioxide in silica fume reacts with calcium hydroxide to form a hydrated calcium silicate gel with higher strength and excellent stability, which optimizes the composition of the gel and improves the quality. The products have better compression, flexural, impermeability, corrosion, impact and wear resistance. The addition of gypsum can control the hydration rate of cement. It can work with silica fume and liquid components to adjust the hydration reaction time and then adjust the setting time, so that the setting speed and hardening time are optimized, thereby improving the overall strength of artificial aggregate products and reducing shrinkage deformation.

[0009] Water glass has a certain viscosity and is easier to form spherical aggregates; the addition of water reducer enhances the dispersibility of cement particles and effectively enhances the fluidity of cement mixtures. At the same time, the water reducer plays a lubricating and steric role to a certain extent, further optimizing the fluidity of cement mixtures and maintaining a stable slump.

[0010] Furthermore, the liquid components include, by weight, 35-55 parts of water glass, 2.5-4.5 parts of sodium hydroxide, 0.2-0.5 parts of water reducer, and 40-65 parts of water, the sum of the components being 100 parts; wherein the modulus of water glass is 1-2.

[0011] Furthermore, based on per cubic meter of artificial aggregate, the powder component also includes 2-5 parts of redispersible latex powder and 1-2 parts of cellulose.

[0012] By adopting the above technical solution, the redispersible latex powder improves the tensile strength of the mixed mortar, thereby enhancing the impact toughness of the mixed mortar, and also gives the cement mixture a stress field dispersion effect. In addition, the redispersible latex powder has a certain water absorption, and together with cellulose, it fully invades the surface of the cementitious material, which can improve the water absorption of the cementitious material surface, and then appropriately delay the interaction time between the cementitious material and the alkaline activator, and further with a certain amount of silica fume, gypsum, water glass and sodium hydroxide, adjust the hardening speed, reduce the cracking of the molybdenum tailings powder artificial aggregate, make the prepared molybdenum tailings powder artificial aggregate strength mostly optimal, and at the same time improve the wear resistance of the molybdenum tailings powder artificial aggregate.

[0013] Furthermore, the liquid component also includes triethanolamine, and the amount of triethanolamine used is 0.005wt% to 0.015wt% of the amount of cement used.

[0014] By adopting the above technical scheme, triethanolamine and its salt solution are used as engineering admixtures and early strength agents in the cement clinker grinding process, which can not only improve the fluidity and packing density of the cement mixture, but also improve the early strength and anti-seepage performance.

[0015] Preferably, the molybdenum tailings powder has a specific surface area of ​​550-650m 2 / kg.

[0016] By adopting the above technical solution, controlling the specific surface area of ​​the molybdenum tailings powder can make the molybdenum tailings artificial aggregate have an excellent contact area and a more compact structure. At the same time, the molybdenum tailings powder can be fully dispersed in the cement mixture.

[0017] Preferably, the water reducer is selected from one of a lignin-based water reducer, a naphthalenesulfonate-based water reducer, a water-soluble resin water reducer, and a polycarboxylic acid-based water reducer.

[0018] By adopting the above technical solution, the type of water reducing agent is limited, so that the cement mixture has a high-efficiency water-reducing effect and maintains excellent fluidity and slump.

[0019] Preferably, the cellulose is selected from one of methyl cellulose ether, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.

[0020] In a second aspect, the present invention further provides a method for preparing molybdenum tailings powder artificial aggregate, which is applied to the above-mentioned molybdenum tailings powder artificial aggregate, comprising the following steps:

[0021] Step (1), weighing and mixing molybdenum tailings powder, cement, slag powder and silica fume according to the formula amount to obtain a powder component;

[0022] Step (2), mixing water glass, sodium hydroxide, a water reducing agent and water according to the formula amount to obtain a liquid component;

[0023] Step (3), the powder component obtained in step (1) is continuously stirred, and the liquid component obtained in step (2) is uniformly sprayed into the mixture according to the formula amount, and the mixture is mixed into a spherical artificial aggregate preform;

[0024] Step (4), stacking the spherical artificial aggregate preforms obtained in step (3) and covering them with a plastic film for natural curing for 28 days to obtain molybdenum tailings artificial aggregate.

[0025] By adopting the above technical solution, the components are mixed in proportion and formed into spheres, and then the molybdenum tailings artificial aggregate can be obtained by curing. The preparation method does not require calcination and sintering, and does not require a steaming process, thereby realizing the resource utilization of molybdenum tailings.

[0026] Furthermore, 1-4 parts of gypsum, 2-5 parts of redispersible latex powder, and 1-2 parts of cellulose are added to the step (1); and / or triethanolamine is added to the step (2), wherein the amount of triethanolamine added is 0.005wt% to 0.015wt% of the amount of cement used.

[0027] In the third aspect, an application of molybdenum tailings powder artificial aggregate adopts the following technical solution:

[0028] An application of molybdenum tailings powder artificial aggregate, using any of the above-mentioned molybdenum tailings artificial aggregates to apply to concrete.

[0029] By adopting the above technical solution, molybdenum tailings artificial aggregate is used as the raw material of concrete, which ensures the compressive strength of concrete while making resource utilization of molybdenum tailings. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the examples. For the sake of simplicity of description, this document cannot enumerate all the alternative technical features and implementation schemes included in the present invention, so those skilled in the art should know that any technical features and implementation schemes in this embodiment do not limit the scope of protection of the present invention, and the scope of protection includes any alternative technical features and implementation schemes taken by all those skilled in the art without creative work. Specifically, the implementation schemes obtained by replacing any technical feature in the present invention or combining any two or more technical features provided by the present invention should be within the scope of protection of the present invention. If the specific techniques and conditions are not indicated in the examples, they are carried out according to the techniques and conditions described in the literature in this field or according to the product instructions. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially. For example, the specific components used in the following examples are as follows:

[0031] Molybdenum tailings powder: specific surface area 550-650m 2 / kg;

[0032] Cement: Cement with a grade of p.o42.5 or above can be used;

[0033] Slag powder: S95 and above can be used;

[0034] Silica fume: silicon dioxide content 90% and above;

[0035] Gypsum: Commercially available desulfurized gypsum controls cement hydration speed, adjusts setting time, improves product strength, and reduces shrinkage and deformation;

[0036] Redispersible latex powder: polymer modified material, bridged in the product, as an elastic link between the components, making it flexible, and the modified network structure enables the product to resist impact without damage;

[0037] Water glass and sodium hydroxide: add sodium hydroxide to commercially available sodium silicate solution to adjust the modulus of water glass

[0038] 1.0-2.0, reacts with calcium dioxide and aluminum oxide contained in the cementitious material in the powder component to form geopolymers, and stimulates the powder to undergo hydration reaction;

[0039] Water reducer: A commonly used admixture in mixing plants, with a solid content of more than 30% and a water reduction rate of more than 25%. It can reduce water and maintain collapse, maintaining the fluidity and workability of the mixture.

[0040] Example 1

[0041] The molybdenum tailings powder artificial aggregate provided in this embodiment includes a powder component and a liquid component. The powder component includes the following components per cubic meter of artificial aggregate: 50 parts of molybdenum tailings powder, 25 parts of cement, 12 parts of slag powder, 5 parts of silica fume, 4 parts of gypsum, and 1 part of cellulose; the liquid component accounts for 15.7% of the powder component. Among them, in the liquid component, the liquid component includes, by weight, 35 parts of water glass, 2.5 parts of sodium hydroxide, 0.4 parts of water reducer, and 62.1 parts of water.

[0042] Among them, the specific surface area of ​​molybdenum tailings powder is 550m 2 / kg; water glass modulus is 1; cement grade is 42.5; water reducing agent is lignin sulfonate.

[0043] The preparation method thereof comprises the following steps:

[0044] Step (1), weighing and mixing molybdenum tailings powder, cement, slag powder, silica fume, gypsum and cellulose according to the formula amount to obtain a powder component;

[0045] Step (2), dissolving and mixing water glass, sodium hydroxide, a water reducing agent and water according to the formula amount to obtain a liquid component;

[0046] Step (3), the powder component obtained in step (1) is continuously stirred, and the liquid component obtained in step (2) is uniformly sprayed into the mixture according to the formula amount, and the mixture is mixed into a spherical artificial aggregate preform;

[0047] Step (4), stacking the spherical artificial aggregate preforms obtained in step (3) and covering them with a plastic film for natural curing for 28 days to obtain molybdenum tailings artificial aggregate.

[0048] A molybdenum tailings powder artificial aggregate is provided in Examples 2-5. The composition of the powder component and the mass percentage of the liquid component in the powder component per cubic meter of artificial aggregate are shown in Table 1, wherein the content of each component in the composition of the liquid component in each embodiment is calculated in parts by weight of the liquid component, as shown in Table 2.

[0049] Table 1 Composition of molybdenum tailings powder artificial aggregate per cubic meter

[0050]

[0051]

[0052] Table 2

[0053]

[0054] Example 2

[0055] The present embodiment provides a molybdenum tailings powder artificial aggregate, the specific composition of which is shown in Table 1 and Table 2, wherein the liquid component is 23.4w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 1; the water reducer is a polycarboxylic acid water reducer. The preparation method is the same as that of Example 1.

[0056] Example 3

[0057] The present embodiment provides a molybdenum tailings powder artificial aggregate, the specific composition of which is shown in Table 1 and Table 2, wherein the liquid component is 31.2w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 650m 2 / kg; water glass modulus is 1; the water reducer is a polycarboxylic acid water reducer. The preparation method is the same as that of Example 1.

[0058] Example 4

[0059] The present embodiment provides a molybdenum tailings powder artificial aggregate, the specific composition of which is shown in Table 1 and Table 2, wherein the liquid component is 30.5w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 2; the water reducer is a naphthalenesulfonate water reducer. The preparation method is the same as that of Example 1.

[0060] Example 5

[0061] The present embodiment provides a molybdenum tailings powder artificial aggregate, the specific composition of which is shown in Table 1 and Table 2, wherein the liquid component is 34.7w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 1; the water reducer is a water-soluble resin water reducer. The preparation method is the same as that of Example 1.

[0062] Examples 6-10 provide a molybdenum tailings powder artificial aggregate, and the composition of the powder component and the mass percentage of the liquid component in the powder component per cubic meter of artificial aggregate are shown in Table 3, wherein the content of each component in the composition of the liquid component in each embodiment is shown in Table 4 in terms of the weight percentage of the liquid component.

[0063] Table 3

[0064]

[0065] Table 4

[0066]

[0067] Example 6

[0068] The molybdenum tailings powder artificial aggregate provided in this embodiment, per cubic meter of molybdenum tailings powder artificial aggregate, the composition of the powder component and the mass percentage of the liquid component in the powder component are shown in Table 3, wherein the content of each component in the composition of the liquid component in each embodiment is calculated by weight of the liquid component, see Table 4. In this embodiment, the specific surface area of ​​the molybdenum tailings powder is 550m 2 / kg, the water glass modulus is 1, the cement grade is 42.5, the water reducer is a lignin-based water reducer, and the cellulose is methyl cellulose ether.

[0069] The preparation method thereof comprises the following steps:

[0070] Step (1), weighing and mixing molybdenum tailing powder, cement, slag powder, silica fume, gypsum, redispersible latex powder and cellulose according to the formula amount to obtain a powder component;

[0071] Step (2), dissolving and mixing water glass, sodium hydroxide, water reducing agent, water and triethanolamine according to the formula amount to obtain a liquid component;

[0072] Step (3), the powder component obtained in step (1) is continuously stirred, and the liquid component obtained in step (2) is uniformly sprayed into the mixture according to the formula amount, and the mixture is mixed into a spherical artificial aggregate preform;

[0073] Step (4), stacking the spherical artificial aggregate preforms obtained in step (3) and covering them with a plastic film for natural curing for 28 days to obtain molybdenum tailings artificial aggregate.

[0074] Example 7

[0075] The molybdenum tailings powder artificial aggregate provided in this embodiment has a composition ratio of powder component and liquid component as shown in Table 3 and Table 4, wherein the liquid component is 24.3w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 1; the water reducer is a polycarboxylic acid water reducer, and the cellulose is methyl cellulose. The preparation method is the same as that of Example 6.

[0076] Example 8

[0077] In the molybdenum tailings powder artificial aggregate provided in this embodiment, the composition ratio of the powder component and the liquid component is shown in Table 3 and Table 4, wherein the liquid component is 30.5w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 650m 2 / kg; water glass modulus is 1; the water reducer is a polycarboxylic acid water reducer, and the cellulose is hydroxypropyl methylcellulose. The preparation method is the same as that of Example 6.

[0078] Example 9

[0079] The molybdenum tailings powder artificial aggregate provided in this embodiment has a composition ratio of powder component and liquid component as shown in Table 3 and Table 4, wherein the liquid component is 29.8w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 2; the water reducer is a naphthalenesulfonate water reducer, and the cellulose is hydroxyethyl cellulose. The preparation method is the same as that of Example 6.

[0080] Example 10

[0081] The molybdenum tailings powder artificial aggregate provided in this embodiment has a composition ratio of powder component and liquid component as shown in Table 3 and Table 4, wherein the liquid component is 31.4w% of the powder component; the specific surface area of ​​the molybdenum tailings powder is 600m 2 / kg; water glass modulus is 1; the water reducer is a water-soluble resin water reducer, and the cellulose is methyl cellulose ether. The preparation method is the same as that of Example 6.

[0082] Comparative Example 1

[0083] In Comparative Example 1, compared with Example 7, an equal amount of gypsum was replaced by sodium hydroxide, and the composition of other raw materials remained unchanged.

[0084] Comparative Example 2

[0085] In Comparative Example 2, compared with Example 7, an equal amount of gypsum is replaced with silica fume, and the composition of other raw materials remains unchanged.

[0086] Comparative Example 3

[0087] In Comparative Example 3, compared with Example 7, an equal amount of redispersible latex powder is replaced by cellulose, and the composition of other raw materials remains unchanged.

[0088] Comparative Example 4

[0089] In Comparative Example 4, compared with Example 7, an equal amount of cellulose is replaced by redispersible latex powder, and the composition of other raw materials remains unchanged.

[0090] Performance Testing

[0091] The crushing value index, water absorption rate, apparent density, firmness and radioactivity of the molybdenum tailings artificial aggregate provided by Examples 1-10 and Comparative Examples 1-4 were tested for performance, as shown in Table 5 below.

[0092] Table 5

[0093]

[0094] From the test results of Examples 1 to 10 and Comparative Examples 1 to 4, it can be seen that gypsum, water glass and sodium hydroxide work synergistically, combined with a certain amount of silica fume, can be used to adjust the hydration rate of the gel material to obtain a suitable hydration rate, thereby ensuring that the molybdenum tailings aggregate has physical properties.

[0095] Application Example 1

[0096] This application example uses the molybdenum tailings artificial aggregate provided in Example 7 to be applied to the components of C10, C20, and C30 strength grade concrete.

[0097] Application Example 2

[0098] This application example uses the molybdenum tailings artificial aggregate provided in Example 8 to be applied to the components of C10, C20, and C30 strength grade concrete.

[0099] The concrete components of different strength grades provided in Application Example 1 are shown in Table 6 below, and the concrete components of different strength grades provided in Application Example 2 are shown in Table 7 below.

[0100] Table 6

[0101]

[0102] Table 7

[0103]

[0104] For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived from them are still within the scope of protection of the claims of the invention.

Claims

1. A molybdenum tailings powder artificial aggregate, characterized in that: The invention is composed of a powder component and a liquid component. The powder component is composed of the following components in parts by weight per cubic meter of artificial aggregate: 50-70 parts of molybdenum tailings powder, 10-25 parts of cement, 3-12 parts of slag powder, 5-10 parts of silica fume, 1-4 parts of gypsum, 1-2 parts of cellulose, and 2-5 parts of redispersible latex powder; the liquid component accounts for 15wt%-35wt% of the mass percentage of the powder component; the liquid component is composed of the following components in parts by weight: 35-55 parts of water glass, 2.5-4.5 parts of sodium hydroxide, 0.2-0.5 parts of water reducer, 40-65 parts of water, and triethanolamine, wherein the amount of triethanolamine used is 0.005wt%-0.015wt% of the amount of cement used, and the water glass modulus is 1-2.

2. The molybdenum tailings powder artificial aggregate according to claim 1, characterized in that: The molybdenum tailings powder has a specific surface area of ​​550-650m 2 / kg.

3. The molybdenum tailings powder artificial aggregate according to claim 2, characterized in that: The water reducer is selected from a lignin-based water reducer, a naphthalenesulfonate-based water reducer, a water-soluble resin water reducer, and a polycarboxylic acid-based water reducer.

4. The molybdenum tailings powder artificial aggregate according to claim 1, characterized in that: The cellulose is selected from one of methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.

5. A method for preparing molybdenum tailings powder artificial aggregate, applied to the molybdenum tailings powder artificial aggregate according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step (1), weighing and mixing molybdenum tailing powder, cement, slag powder, silica fume, gypsum, redispersible latex powder and cellulose according to the formula amount to obtain a powder component; Step (2), uniformly mixing triethanolamine, water glass, sodium hydroxide, a water reducing agent and water according to the formula amount to obtain a liquid component; Step (3), the powder component obtained in step (1) is continuously stirred, and the liquid component obtained in step (2) is uniformly sprayed into the mixture according to the formula amount, and the mixture is mixed into a spherical artificial aggregate preform; Step (4), stacking the spherical artificial aggregate preforms obtained in step (3) and covering them with a plastic film for natural curing for 28 days to obtain molybdenum tailings artificial aggregate.

6. An application of molybdenum tailings powder artificial aggregate, characterized in that: The molybdenum tailings powder artificial aggregate described in any one of claims 1 to 4 is applied to concrete.

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